Field of the Invention
The present invention relates to a Spectrum Sharing System (SSS) and method which allows Radio Frequency (RF) wireless mobile and fixed devices to operate in the 3100-3650 MHz frequency band while simultaneously protecting radar operations from interference. The SSS includes equipment which utilizes spectrum sensing, GPS data, and database technology to provide a solution by which mobile and fixed wireless devices can be allowed use of the 3100-3650 MHz frequency band and share same spectrum with radar systems. The spectrum sharing action is only possible when radar emissions are not detected within the licensed service in the 3100-3650 MHz spectrum, and SSS has determined that geographical area of interest is not occupied by radar systems.
Description of the Related Art
Due to an extremely high demand for additional radio communication spectrum that could provide service to mobile and fixed wireless communication devices, new methods and systems are needed to provide technical solutions and to accommodate the spectrum expansion. The FCC is in process of creating additional regulations for Part 96 in order to reallocate licensed spectrum within 3100-3650 MHz that was traditionally utilized for radar operations. Spectrum that is used by radar systems is referenced to as RADIOLOCATION spectrum, and radar operations allocated for radar operations are referred to as a “type of service”. The evolving FCC regulations would ensure that reallocated spectrum would have to continue to serve the primary and existing radar spectrum users, but also to accommodate new communication capability for mobile and fixed wireless devices within the same spectrum.
The spectrum discussed in this patent would be allocated for both (radar) RADIOLOCATION and FIXED and MOBILE on co-primary basis. The FIXED and MOBILE would be represented by commercial wireless devices such as mobile cell/smart phones, mobile communication devices, or fixed or stationary wireless data communication devices. The regulatory statute may, or may not provide details how systems design should be accomplished, or implemented. Never the less the 3.5 GHz FCC Notice of Proposed Rulemaking (NPRM) and FCC Report and Order draft rules specify that wireless mobile and fixed devices should cease their operations if presence of radar systems has been detected within a certain timeframe. The detection of a radar signal could be accomplished either via spectrum sensing means, or via sensing and RF propagation calculations. Once a radar signal was detected, the SSS and certain SSS elements would take action to deactivate CBSD units which could cause interference to an incumbent radar system. Via an internal process, the SSS would determine geographical areas in which CBSD units could cause interference to the incumbent radar systems. The geographical areas in which CBSD devices are not allowed to operate are referenced as protection/sharing zones in this patent. The SSS would create geographical protection zones in which CBSD units would be deactivated for a certain period of time. In the evolving spectrum environment, the mobile and fixed wireless devices would have to protect radar systems from interference that could originate from mobile and fixed wireless devices Radio Frequency (RF) emissions. The spectrum sharing, between primary spectrum users which are radar systems and mobile wireless network devices as well as fixed wireless network devices, in the impacted spectrum would be implemented via a system method that in this patent is called the Spectrum Sharing System (SSS).
Protocols, Standards, and waveforms used to facilitate and to support communications, data communications and data throughput by the Spectrum Sharing System network and mobile as well as fixed wireless (Level 1 and Level 2) devices referenced in this patent are listed in. Also ability by the wireless devices referenced in this patent to access spectrum and frequency bands listed in this patent and supported by protocols and includes following standards but not limited to: LTE; LTE Advanced; 3 GPP; WiMax 802.16, 3G, 2G,
Mobile and Fixed Wireless Devices in this patent are also referred to as End user data communication devices and are also segregated into as Level 1 wireless devices and Level 2 wireless devices in this embodiment for 3550-3650 MHz frequency band.
Level 1 wireless device also called Priority Access Device has a higher regulatory standing over Level 2 wireless device also called General Access Device. Level 1 wireless device must be protected from interference that would be generated by Level 2 wireless device(s).
Level 2 wireless devices also called General Access Device has a lower regulatory priority than Level 1 wireless device also called Priority Access device. Level 2 must not cause interference to Level 1 wireless device(s). Level 2 wireless devices must take corrective steps to mitigate interference it caused to Level 1 wireless device(s).
Terminology and Nomenclatures Explained:
SSS: Spectrum Sharing System is a system which is comprised of a number of main elements and includes CBSD, Spectrum Sensor also referred to as Environmental Sensing Capability, and End Users. The SSS has information of lat/long of each CBSD units within its domain. The SSS ensures that CBSD units take appropriate actions and that spectrum regulatory framework is followed and enforced per FCC Rules and regulations. Upon determination that radar signal has been detected within its geographic domain, SSS will establish dynamic protection zones so that CBSD and End User devices do not interfere with radar operations in the said spectrum.
Dynamic Protection/sharing Zones: In this embodiment protection zones are also referred to or also called protection/sharing zones. Protection zones may also be called or referred to as geographic protection zones in this patent. Protection zones are Geographical Areas depicted and identified by a set of multiple Latitude and Longitude points in which CBSD and, or End User devices are not allowed to operate for a certain period of time and while radar emissions are being detected by the spectrum sensor, also called the environmental spectrum sensor (ESC).
CBSD Devices: Citizens Broadband Radio System (CBSD) RF wireless devices which serve as Hubs, Access Points, within said spectrum and can support and provide communications to the End User devices. CBSD are GPS enabled devices which communicate with SSS. Once notified that radar signal has been detected, CBSD disables communication channels with end users within N*60 seconds time frame. In certain configurations CBSD may, or can possess spectrum sensing, or environmental sensing capability. (N can be a number 1-5, integer or numeric and can represent decimal numbers).
Spectrum Sensor, or also called or referred to as an Environmental Spectrum Sensor: A RF device which detects radar signals and differentiates between communication signals and radar signals. The same device informs SSS and CBSD units that a radar signal has been detected within the SSS geographic domain. In certain configurations the spectrum sensor can be an independent, stand-alone device, or in a separate network configuration the spectrum sensing capability also referred to as the spectrum sensing capability can be integrated into the CBSD units. The spectrum sensor can also be disposed directly within the wireless or end user devices. That is, these latter devices will be designed to operate in a shared spectrum system with a radar system in the 3100-3650 MHz spectrum.
End User Devices: RF Wireless devices used by consumers for voice and broadband digital/data communications. The End User Devices will deactivate per commands issued by CBSD devices,
Free Space Loss Equation: An equation which establishes RF signal loss by utilizing RF signal frequency in MHz, and distance the RF signal travels in meters, or kilometers.
RF Propagation Models and Path Loss equations: Equations and RF propagation models used by RF engineering community to calculate RF signal loss as the RF signal travels from one point to another point on the face of the earth. Such RF models may include terrain and clutter losses caused by terrain such as mountains, hills, clutter or even manmade obstacles.
dBm or decibel-milliwatt—dBm is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW).                dBW or decibel watt—a unit of power in decibel scale referenced to one watt (W). Watt (abbreviated W)—the International System of Units' (SI) standard unit of power (energy per unit time), the equivalent of one joule per second. The watt is used to specify the rate at which electrical energy is dissipated, or the rate at which electromagnetic energy is radiated, absorbed, or dissipated.RF—Radio FrequencyMHz is MegahertzLatitude also abbreviated as Lat in this patent.Longitude also abbreviated as Long, or Lng.ESC=Environmental sensing capability; also called and referred to as the spectrum sensor in this patent.PA (Priority Access)=Level 1 End User Wireless Device.GA (General Access)=Level 2 End User Wireless DeviceProtection zones: also referred to as protection/sharing zones and also referred to as geographic protection zones. Protection Zones are in geographical areas in which CBSD units are not allowed to provide communications to the wireless end users after radar signals have been detected. The CBSD units within geographic protection zones are prevented from providing communication services to the PA and GA wireless users for as long as radar signals are being detected, and potentially for a certain period of time after radar emissions cease to be detected.These demanding features may require wide bandwidth operation or covering operation across several frequency bands. This provides motivation for comprehensive and efficient utilization of the available spectrum. The effort to overcome inefficient and highly underutilized spectrum resources has led to concept of cognitive radio (CR). A CR system is based on structural design of software-defined radio intended to enhance spectrum utilization efficiency by interacting with the operating environment. A CR-based system must be aware of its environment by sensing spectrum usage and have the capability to switch over the operating points among different unoccupied frequency bands. A CR-based system may cover various features, including sensing the spectrum of nearby devices, switching between different frequency bands, and power level adjustment of transmitting antennas.        